Popcorn is an unexpected offering at a cocktail reception but tastes delightfully sophisticated when flavored with a Southwestern-inspired blend of cumin, coriander, red pepper, and lime juice.
Place cumin seeds, coriander seeds, and red-pepper flakes in a spice grinder, and process until fine. Transfer to a small bowl; add garlic powder, pepper, and mustard, and stir to combine. Set aside.
Heat a 4-quart pot over medium-high heat, and add oil. When oil is hot, pour in kernels. Cover, and let stand over heat until first kernel pops. Shake pan gently, close to heat; continue shaking until kernels stop popping, 4 to 5 minutes.
In a small skillet over medium heat, bring lime juice to a boil. Lower heat, and cook until liquid is reduced to 1/2 tablespoon. Add the butter, and swirl it to melt; add spice mixture. Drizzle over popcorn while stirring to coat evenly. Sprinkle with salt to taste, and toss. This recipe is best eaten the day it is prepared.
The dry spice mixture can be made in advance and stored in an airtight container away from heat and light up to six months.